(a) Field of the Invention
This disclosure relates to a method of preparing a fullerene aggregate and the aggregate. More specifically, this disclosure relates to a method of preparing a C70 aggregate that is aggregated to a well-defined shape, and optical properties of the C70 aggregate.
(b) Description of the Related Art
Preparation of a light emission source that emits light from an organic molecule or organic molecular system is important in the large-scale production of electronic equipment and photoelectronic equipment of the next generation with low cost. Further, it is expected that use of the organic light emission source may contribute to light weight and flexibility of the compositional material of the next generation electronic equipment or photoelectronic equipment. Light emission occurring by recombination of excitons requires a specific energy bandgap, and it is known that in order for the organic light emission source to satisfy the condition, an organic molecule with a high degree of conjugated double bonds should exist as a crystal structure
Fullerene including C70 and C60 (Buckminster fullerene) and are a carbon allotrope, the whole molecule consists of conjugated double bonds, and it has a specific energy bandgap that may be easily controlled by doping, and thus has received a lot of attention. Further, since fullerene may have semiconductivity and superconductivity, it is a promising future electronic equipment material. Meanwhile, fullerene has a drawback that the photoluminescence characteristic is not excellent, contrary to the excellent electrical characteristic, and thus it has a limitation for use as a light emission source.
Recently, it has been reported that if C60 exists as a specific ensemble in a powder phase or a solution phase, the fluorescent characteristic may be improved, and C60 has received attention. Although a lot of studies have progressed on C60, studies on C70 are relatively insufficient.